This invention relates to a ship for transporting a number of barges or lighters carried above and below its main deck, and more specifically to such a barge-carrying ship capable of transferring the barges from and to the water surfaces at one end of the ship.
Conventional barge-carrying ships of the aforementioned character include the one illustrated in FIG. 1. The ship has on its upper deck a traveling crane a for handling barges. The barges c are hoisted at the stern and are stowed and stacked in holds via hatch openings b of the upper deck. In addition, they are also carried on the hatch covers.
The ship thus requires many hatch openings and transverse bulkheads or barge guides. Accordingly, the barges placed above and below the deck leave so much unused space in front and in the rear that the number of such craft to be carried is limited.
An additional problem arises from the fact that the traveling crane a, which is the only means for transferring the barges, requires much time to move the barges up and down and back and forth, with a consequent slowing of the cargo handling operation.
A barge-carrying ship of another conventional design is shown in FIG. 2. This type lifts barges e by means of an elevator d at the stern, moves a truck f from the deck into the space under each barge in the lifted position, and then lowers and carries the barge on the truck for subsequent shipboard stowage. Among the problems of this ship are the inability to utilizing the hold spaces below the lower deck for barge accommodation, impossibility of shifting barge from the space above the upper deck to that above the lower deck and vice versa, and the difficulty in sorting the barges by the ports of destination, particularly when the ship is to call on many ports, because of the limited number of decks available.
The object of the present invention is the provision of a barge-carrying ship which overcomes the aforementioned problems. Thus, the invention aims to provide a ship capable of carrying an increased number of barges with an improved loading and unloading efficiency and ease of trimming, the vessel itself being simplified in construction.